Interannual Variation in Seed Traits of Cedrela Species: Implications for Conservation in the Context of Climate Change.

Abstract

Climate change is altering temperature and precipitation regimes in Argentina, with potential consequences for regeneration and persistence of forest tree species, emphasizing the importance of ex situ seed conservation. We evaluated interannual variation in seed traits, desiccation tolerance, storage behavior, and longevity of Cedrela balansae C. DC. and C. fissilis Vell. (Meliaceae), two endangered native species of subtropical rainforests in Argentina. Both species produced desiccation-tolerant seeds, independently of collection year, seed traits, or climatic conditions. Depending on the species, seed traits and longevity varied across years and showed strong relationships with temperature and precipitation, particularly during seed development. Cedrela balansae seeds are medium-lived seeds and have high longevity under standard seed banking conditions, suggesting strong potential for long-term ex situ conservation. Cedrela fissilis seeds are short-lived seeds and have high sensitivity to the storage environment. Correlations among climatic variables and seed traits and longevity parameters suggest that future warming and drying environments may shorten the window for germination and seedling establishment, with species-specific responses depending on climatic conditions during seed development. These results highlight the importance of climate effects in determining seed traits and seed longevity and emphasize the role of seed banking as a critical conservation strategy under climate change.